Nah, gambling isn't wrong as long as you don't gamble excessively. It becomes wrong when you gamble all that you have even the money that you should use to buy food. When you can't control yourself not to gamble specially when your losing. You should understand just gamble what you can afford to lose.
Oh well, that's what others forgot. When they gamble they are like horse and probably looking on just one direction without even leaning back. That's what makes gambling wrong. Sometimes a gambler even if they don't have food to eat they do gamble having a false hope that they will win.
You called them a irresponsible gambler who will prioritize gambling over their basic needs, I have seen that kind of people in my area all day and all they do is just to gamble instead of taking care the needs of their family, in the end they will blame the government for their negligence.